DDR2(+LP) Compliance Testing Methods of Implementation
61
Single-Ended Signals AC Input Parameters Tests
4
PASS Condition
The voltage level at tDS (DM and DQ input setup time in JEDEC specification) before DQS midpoint
for the high level voltage shall be greater than or equal to the minimum V
IH(AC)
value.
Measurement Algorithm
1 Acquire and split read and write bursts of the acquired signal.
2 Take the first valid WRITE burst found.
3 Find all valid rising DQ crossings that cross V
IH(AC)
in the burst.
4 For all DQ crossings found, locate all the following DQS crossings that cross 0V.
5 Calculate the time where the test result is taken. Calculation is expressed as:
T
TESTRESULT
= T
DQS MIDPOINT
- tDS.
(tDS - DM and DQ input setup time in JEDEC specification which is due to speed grade.)
6 Take voltage level of DQ signal at T
TESTRESULT
as the test result for V
IH(AC)
.
7 Collect all V
IH(AC)
.
8 Determine the worst result from the set of V
IH(AC)
measured.
Summary of Contents for D9020DDRC
Page 1: ...Keysight D9020DDRC DDR2 LP Compliance Test Application Methods of Implementation ...
Page 10: ...10 DDR2 LP Compliance Testing Methods of Implementation ...
Page 46: ...2 Preparing to Take Measurements 30 DDR2 LP Compliance Testing Methods of Implementation ...
Page 70: ...3 Measurement Clock Tests 54 DDR2 LP Compliance Testing Methods of Implementation ...
Page 224: ...14 Clock Timing CT Tests 208 DDR2 LP Compliance Testing Methods of Implementation ...
Page 270: ...15 Data Strobe Timing DST Tests 254 DDR2 LP Compliance Testing Methods of Implementation ...